/*
 * Copyright 2001-2005 (C) MetaStuff, Ltd. All Rights Reserved.
 *
 * This software is open source.
 * See the bottom of this file for the licence.
 */

package org.dom4j;

import java.util.List;
import java.util.Map;

import org.jaxen.FunctionContext;
import org.jaxen.NamespaceContext;
import org.jaxen.VariableContext;

/**
 * <p> <code>XPath</code> represents an XPath expression after it has been
 * parsed from a String. </p>
 * 
 * @author <a href="mailto:james.strachan@metastuff.com">James Strachan </a>
 * @version $Revision: 1.2 $
 */
public interface XPath extends NodeFilter
{
   /**
    * <p> <code>getText</code> will return the textual version of the XPath
    * expression. </p>
    * 
    * @return the textual format of the XPath expression.
    */
   String getText();

   /**
    * <p> <code>matches</code> returns true if the given node matches the
    * XPath expression. To be more precise when evaluating this XPath expression
    * on the given node the result set must include the node. </p>
    * 
    * @param node DOCUMENT ME!
    * 
    * @return true if the given node matches this XPath expression
    */
   boolean matches(Node node);

   /**
    * <p> <code>evaluate</code> evaluates an XPath expression and returns the
    * result as an {@link Object}. The object returned can either be a {@link
    * List} of {@link Node}instances, a {@link Node}instance, a {@link String}
    * or a {@link Number}instance depending on the XPath expression. </p>
    * 
    * @param context is either a node or a list of nodes on which to evalute the
    *           XPath
    * 
    * @return the value of the XPath expression as a {@link List}of {@link
    *         Node} instances, a {@link Node}instance, a {@link String}or a
    *         {@link Number}instance depending on the XPath expression.
    */
   Object evaluate(Object context);

   /**
    * <p> <code>selectObject</code> evaluates an XPath expression and returns
    * the result as an {@link Object}. The object returned can either be a
    * {@link List} of {@link Node}instances, a {@link Node}instance, a {@link
    * String} or a {@link Number}instance depending on the XPath expression.
    * </p>
    * 
    * @param context is either a node or a list of nodes on which to evalute the
    *           XPath
    * 
    * @return the value of the XPath expression as a {@link List}of {@link
    *         Node} instances, a {@link Node}instance, a {@link String}or a
    *         {@link Number}instance depending on the XPath expression.
    * 
    * @deprecated please use evaluate(Object) instead. WILL BE REMOVED IN
    *             dom4j-1.6 !!
    */
   Object selectObject(Object context);

   /**
    * <p> <code>selectNodes</code> performs this XPath expression on the given
    * {@link Node}or {@link List}of {@link Node}s instances appending all the
    * results together into a single list. </p>
    * 
    * @param context is either a node or a list of nodes on which to evalute the
    *           XPath
    * 
    * @return the results of all the XPath evaluations as a single list
    */
   List selectNodes(Object context);

   /**
    * <p> <code>selectNodes</code> evaluates the XPath expression on the given
    * {@link Node}or {@link List}of {@link Node}s and returns the result as a
    * <code>List</code> of <code>Node</code> s sorted by the sort XPath
    * expression. </p>
    * 
    * @param context is either a node or a list of nodes on which to evalute the
    *           XPath
    * @param sortXPath is the XPath expression to sort by
    * 
    * @return a list of <code>Node</code> instances
    */
   List selectNodes(Object context, XPath sortXPath);

   /**
    * <p> <code>selectNodes</code> evaluates the XPath expression on the given
    * {@link Node}or {@link List}of {@link Node}s and returns the result as a
    * <code>List</code> of <code>Node</code> s sorted by the sort XPath
    * expression. </p>
    * 
    * @param context is either a node or a list of nodes on which to evalute the
    *           XPath
    * @param sortXPath is the XPath expression to sort by
    * @param distinct specifies whether or not duplicate values of the sort
    *           expression are allowed. If this parameter is true then only
    *           distinct sort expressions values are included in the result
    * 
    * @return a list of <code>Node</code> instances
    */
   List selectNodes(Object context, XPath sortXPath, boolean distinct);

   /**
    * <p> <code>selectSingleNode</code> evaluates this XPath expression on the
    * given {@link Node}or {@link List}of {@link Node}s and returns the
    * result as a single <code>Node</code> instance. </p>
    * 
    * @param context is either a node or a list of nodes on which to evalute the
    *           XPath
    * 
    * @return a single matching <code>Node</code> instance
    */
   Node selectSingleNode(Object context);

   /**
    * <p> <code>valueOf</code> evaluates this XPath expression and returns the
    * textual representation of the results using the XPath string() function.
    * </p>
    * 
    * @param context is either a node or a list of nodes on which to evalute the
    *           XPath
    * 
    * @return the string representation of the results of the XPath expression
    */
   String valueOf(Object context);

   /**
    * <p> <code>numberValueOf</code> evaluates an XPath expression and returns
    * the numeric value of the XPath expression if the XPath expression results
    * is a number, or null if the result is not a number. </p>
    * 
    * @param context is either a node or a list of nodes on which to evalute the
    *           XPath
    * 
    * @return the numeric result of the XPath expression or null if the result
    *         is not a number.
    */
   Number numberValueOf(Object context);

   /**
    * Retrieve a boolean-value interpretation of this XPath expression when
    * evaluated against a given context.
    * 
    * <p> The boolean-value of the expression is determined per the
    * <code>boolean(..)</code> core function as defined in the XPath
    * specification. This means that an expression that selects zero nodes will
    * return <code>false</code>, while an expression that selects one-or-more
    * nodes will return <code>true</code>. </p>
    * 
    * @param context The node, nodeset or Context object for evaluation. This
    *           value can be null
    * 
    * @return The boolean-value interpretation of this expression.
    * 
    * @since 1.5
    */
   boolean booleanValueOf(Object context);

   /**
    * <p> <code>sort</code> sorts the given List of Nodes using this XPath
    * expression as a {@link java.util.Comparator}. </p>
    * 
    * @param list is the list of Nodes to sort
    */
   void sort(List list);

   /**
    * <p> <code>sort</code> sorts the given List of Nodes using this XPath
    * expression as a {@link java.util.Comparator}and optionally removing
    * duplicates. </p>
    * 
    * @param list is the list of Nodes to sort
    * @param distinct if true then duplicate values (using the sortXPath for
    *           comparisions) will be removed from the List
    */
   void sort(List list, boolean distinct);

   /**
    * DOCUMENT ME!
    * 
    * @return the current function context
    */
   FunctionContext getFunctionContext();

   /**
    * Sets the function context to be used when evaluating XPath expressions
    * 
    * @param functionContext DOCUMENT ME!
    */
   void setFunctionContext(FunctionContext functionContext);

   /**
    * DOCUMENT ME!
    * 
    * @return the current namespace context
    */
   NamespaceContext getNamespaceContext();

   /**
    * Sets the namespace context to be used when evaluating XPath expressions
    * 
    * @param namespaceContext DOCUMENT ME!
    */
   void setNamespaceContext(NamespaceContext namespaceContext);

   /**
    * <p> Sets the current NamespaceContext from a Map where the keys are the
    * String namespace prefixes and the values are the namespace URIs. </p>
    * 
    * <p> For example:
    * 
    * <pre>
    * Map uris = new HashMap();
    * uris.put("SOAP-ENV", "http://schemas.xmlsoap.org/soap/envelope/");
    * uris.put("m", "urn:xmethodsBabelFish");
    * XPath xpath = document
    *         .createXPath("SOAP-ENV:Envelope/SOAP-ENV:Body/m:BabelFish");
    * xpath.setNamespaceURIs(uris);
    * Node babelfish = xpath.selectSingleNode(document);
    * </pre>
    * 
    * </p>
    * 
    * @param map the map containing the namespace mappings
    */
   void setNamespaceURIs(Map map);

   /**
    * DOCUMENT ME!
    * 
    * @return the current variable context
    */
   VariableContext getVariableContext();

   /**
    * Sets the variable context to be used when evaluating XPath expressions
    * 
    * @param variableContext DOCUMENT ME!
    */
   void setVariableContext(VariableContext variableContext);
}

/*
 * Redistribution and use of this software and associated documentation
 * ("Software"), with or without modification, are permitted provided that the
 * following conditions are met:
 * 
 * 1. Redistributions of source code must retain copyright statements and
 * notices. Redistributions must also contain a copy of this document.
 * 
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 * 
 * 3. The name "DOM4J" must not be used to endorse or promote products derived
 * from this Software without prior written permission of MetaStuff, Ltd. For
 * written permission, please contact dom4j-info@metastuff.com.
 * 
 * 4. Products derived from this Software may not be called "DOM4J" nor may
 * "DOM4J" appear in their names without prior written permission of MetaStuff,
 * Ltd. DOM4J is a registered trademark of MetaStuff, Ltd.
 * 
 * 5. Due credit should be given to the DOM4J Project - http://www.dom4j.org
 * 
 * THIS SOFTWARE IS PROVIDED BY METASTUFF, LTD. AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL METASTUFF, LTD. OR ITS CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 * 
 * Copyright 2001-2005 (C) MetaStuff, Ltd. All Rights Reserved.
 */
